The idea that they’re designed to serve as secondary computers is a big part of the opportunity I see for new Web-focused OSes. I think that’s one of the implicit factors that define what people call “netbooks”. How many people use one of those as their one and only computer?

If you start with the assumption that a computer will be a secondary machine — something purchased because it’s cheaper, smaller, and lighter — you can make all sorts of different assumptions about what it needs to be capable of.